Air Lock

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OK,

The sage continues. I went and played with the truck after work and ran the engine diagnostic. It came up with fault codes 6, 7, and 11.

I gather from searching the good old interweb that these are pump speed sensor, throttle position sensor, and A/C switch circuit (or something like that). If it's one of the sensors, then this might make sense-- it gets too cold and the sensor doesn't switch on/off like it should... that's about all I know about sensors. I guess it's time to start learning about engine sensors, etc. If nothing else, I'll know a lot about the 2LTE by the end of this ordeal!
 
Interesting indeed!

I'm not sure if anyone here (perhaps Wayne AKA crushers--I think) has access to a 2LT-E troubleshooting manual. If not, I'd see if I could get an e-mail to a Toyota dealer in Australia (Castle Hill has been great for me).

It's real odd that warming it up makes it start. Mine actually starts right up when cold, or well at temperature. It actually has to crank quite a bit if it's lukewarm.

The Hilux manual I've read says to start it with the throttle 1/2 way down--are you doing this? I never do on mine, but maybe that's what the TPS code is pointing to?

Dan
 
Hi,

My current theory is that it's code "6" that's the issue.

Code 7 is throttle position sensor, and I've actually played around with the throttle position / throttle body about a week ago trying to figure out if it was somehow related to my problems. So, this likely tripped the code 7. Since these codes stay in the system's memory until cleared, this could account for the code 7.

As for code 11, it is "switch signal". From what I gather, it is tripped when you try to start the truck with the A/C on, or when it's not in park or neutral. No doubt, I've likely tried to start it with the A/C button depressed at some point since owning it.

So, that leaves me with code 6. This is listed as "pump speed sensor", "RPM signal" or "crank angle pulse"-- I think they all point to the timing and/or speed of the fuel pump. I'm guessing the speed at which the fuel pump operates is dictated by the RPM of the engine, which it reads via the pump speed sensor. It seems to fit with the symptoms, too in that it might be a fuel pump issue.

I guess I'll have to clear the codes, then try to start it tomorrow and see what codes are tripped. If it's only code 6, I may just disconnect all of the plugs going to the fuel pump, give them a good cleaning and reattach them. Perhaps it's just a corroded terminal somewhere. Otherwise, it might be the timing of the fuel pump, something I'm not sure I have the knowledge to adjust... I think it's done by rotating it somehow in relation to the engine itself, but I'm not sure if that's something I ought to take on.

How this all relates to temperature I don't know.

If anyone has any other ideas, I'm listening, of course.

DanS, I usually don't have my foot on the throttle when trying to start it- I do have the manual throttle / idle knob turned all of the way up, though. I'll try giving it a bit more throttle tomorrow if it won't start.

Cheers
 
your fuel pump will have a way of retarding injection timing for cold weather starts. i am guessing that you have a faulty reading some where that is causing the ECU to inject to late, or to early, but timing will not cause air to enter the fuel system. there would also be some exhaust smoke wile cranking, it will be either white or dark depending if it is injecting to late or to early. if you are sure there is air in the fuel lines it is not a timing issue. hope that helps
 
dtech,

Thanks for the message.

There is no smoke whatsoever when cranking the starter. I've also essentially ruled out air in the lines as I've now replaced all fuel lines and installed two one-way non return valves in the supply line. One is near the fuel tank and one is close to the fuel injector pump up front.

The key seems to be temperature - as soon as the engine or the environment reaches a certain temperature, the truck fires up within the first 1/2 a second of cranking. There is a bit of smoke at first, but that clears up as the engine warms up.

I suspect that it is a sensor issue or something of the like. I think one of the sensors stops working below a certain temperature, or the ecu gets a signal below that temperature to stop the fuel pump from pumping.

I've also just returned from clearing the ecu codes. Then I tried starting it, and now it only shows a code 11. This appears to be "switch signal" which is somewhat ambiguous. I've cleared the codes a few times and it keeps giving me only code 11 now. I also unplugged and replugged all of the connections I could find going to the fuel pump. Visually there was absolutely no corrosion- they looked immaculate.

So, I guess I'm stuck wondering what the code 11 might be. If anyone has come across this, I'd appreciate your help.

Thanks!
 
after reading your post again about the code 11 it seams to me that that code is for a neutral safety or a park safety switch fault or open. all safety switches will be wired in series so if one of them is in open condition it will leave the fuel pump metering valve in a "no fuel" position. thus no smoke no start just cranking. if the colder temp is causing a wire to contract enough to make an open (split in the copper of the wire) in the wire where there is a internal brake it would not allow currant to flow through and appear that one of the safety switches was open and throw a code. find a good wiring diagram for the fuel injection system. do a continuity test when cold enough to not start on systems used to control fuel metering or fuel shut off. if you find a diagram and send it to me i might be able to give you specific instructions on what to look for.
 
2ndGen,

I was busily heating up sensors last night with an IR heating lamp. I stopped paying attention for 5 minutes and saw a bit of smoke coming from the lamp while heating the throttle position sensor :doh:. Luckily, it seems to be working OK after heating the whole thing up with a space heater for an hour last night- it ran fine thereafter. But definitely, heating sensors up one-by-one is a good plan. I will have to use the hair dryer from now on, though! I wonder how my wife will feel when her hair dryer suddenly smells like diesel? :D

dtech,

I think that the "switch circuit" actually prevents the truck from starting (i.e. the pump from pumping fuel) when the AC "amplifier" is running... I suspect that means that it's not only the AC switch that must be switched on, but that the truck must internally somehow have the compressor running. This is likely the case to prevent the batteries from draining completely on starting- they likely couldn't handle the AC and the starter motor on at the same time.

Of course, I say this without having looked at the wiring diagram that 2ndGen posted.

If I can't isolate a sensor with the hair dryer, then I'll likely be stuck trying to diagnose the other circuits. Your theory about the expanding/contracting wire makes a lot of sense in any event.


Thanks for all your help and ideas... keep 'em coming!

:beer:
 
Success (to some extent, anyway)!

I used the "hair dryer method" and warmed up separate bits and pieces tonight and have narrowed it down to this part on the fuel pump (see picture).

I suspected that *this* (see pic) was the fuel solenoid, but I don't know. I had my dad turn the key while I had my hand on it, but I was unable to feel a distinct click- neither when it was warm, nor when it was cool. However, when warmed up with the hair dryer, the truck started right away. I really isolated it, too- the rest of the pump was quite cool.

I also let the whole thing cool down for a few minutes (didn't let the engine warm up in the first place so as not to influence this part) and it wouldn't start with any amount of cranking. Warmed it up with the hair dryer, and presto! It fired right up.

So, anyone know what this part does? Is it the fuel shut off solenoid? If so, why wouldn't I be able to feel it click, even when it was warm and the truck was able to start? Finally, does anyone know how to remove and replace it? I'm really hoping that this repair won't require removal of the injector pump!

In any event, I'm pretty happy to have narrowed it down. Thanks to everyone for their help so far!

Pump1.webp
Pump1.webp
 
Still at it...

OK, so I've been in touch with the local guy here who has access to parts from Japan and he's still waiting for an answer from Japan about part number and cost for the "spill control valve". Everything I've read about this part is that it is a valve which opens and closes to regulate the fuel pressure going to the injectors. I don't know exactly how it's supposed to work, but I gather it closes to allow the pressure to increase prior to injection so that the fuel is injected with more pressure. In essence, I think the valve part of it is controlled by a solenoid.

There's an article about issues with spill control valve in modern engines (most of which use common rail systems, but I think the principle is the same- it looks like the 2LTE is a predecessor to the common rail in that it allows for the increase in pressure, but not at each injector- rather, it's in the pump itself if I'm getting this right). Here's a link to that article anyway:

http://www.dquirk.com/images/PDFs/P...l fuel injectors on low emissions engines.pdf

In any event, I'm guessing that the spill control valve might be seized up somewhat due to crud that's built up around it over the years. I'm also guessing that applying a hair dryer to it and heating it up softens up the crud and allows it to function normally. Then, when it gets colder, it seizes back up in the open (or closed, I haven't figured out which) position.

My idea is to perform a purge of the engine in the hope that it will dissolve some of the build-up (if any). I've seen many links to the procedure and it seems pretty simple. A sample is:

http://www.dieselgiant.com/injectorcleaning.htm

... and for those of you really fascinated by diesel purges, here is a video (ooh, ahh):

http://ca.youtube.com/watch?v=hwCUEjR8ysI

Anyway, I'm just having trouble finding the diesel purge chemical / additive around here. Maybe I'll have to order it. I do have an inline filter and all of the diesel line kicking around so I'll give it a shot as soon as I have the cleaner.

I'll let y'all know what happens.

Cheers,
Max
 
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